Changes

==Pore geometry and clay minerals==

==Pore geometry and clay minerals==

[[file:predicting-reservoir-system-quality-and-performance_fig9-62.png|thumb|300px|{{figure number|3}}After .<ref name=ch09r40>Neasham, J., W., 1977, The morphology of dispersed clay in sandstone reservoirs and its effect on sandstone shaliness, pore space, and fluid flow properties: Proceedings of the SPE Annual Meeting, October 9–12, paper SPE-6858.</ref> Copyright: SPE.]]

[[file:predicting-reservoir-system-quality-and-performance_fig9-62.png|thumb|300px|{{figure number|3}}After Neasham.<ref name=ch09r40>Neasham, J., W., 1977, The morphology of dispersed clay in sandstone reservoirs and its effect on sandstone shaliness, pore space, and fluid flow properties: Proceedings of the SPE Annual Meeting, October 9–12, paper SPE-6858.</ref> Copyright: SPE.]]

[[:file:predicting-reservoir-system-quality-and-performance_fig9-62.png|Figure 3]] shows pore lining and discrete particle clays that decrease porosity and permeability only slightly in contrast to pore-bridging clays, which decrease porosity slightly but substantially lower permeability.

[[:file:predicting-reservoir-system-quality-and-performance_fig9-62.png|Figure 3]] shows pore lining and discrete particle clays that decrease porosity and permeability only slightly in contrast to pore-bridging clays, which decrease porosity slightly but substantially lower permeability.

==Detrital clay and permeability==

==Detrital clay and permeability==

[[file:predicting-reservoir-system-quality-and-performance_fig9-63.png|300px|thumb|{{figure number|4}}After .<ref name=ch09r68>Wilson, M., D., Pittman, E., D., 1977, Authigenic clays in sandstones: recognition and influence on reservoir properties and [[paleoenvironmental analysis]]: Journal of Sedimentary Petrology, vol. 47, no. 1, p. 3–31.</ref> Copyright: Journal of Sedimentary Petrology.]]

[[file:predicting-reservoir-system-quality-and-performance_fig9-63.png|300px|thumb|{{figure number|4}}After Wilson and Pittman.<ref name=ch09r68>Wilson, M., D., Pittman, E., D., 1977, Authigenic clays in sandstones: recognition and influence on reservoir properties and [[paleoenvironmental analysis]]: Journal of Sedimentary Petrology, vol. 47, no. 1, p. 3–31.</ref> Copyright: Journal of Sedimentary Petrology.]]

Detrital clays can be part of sandstone matrix or grains. As matrix, detrital clays can obliterate permeability. Detrital grains of clay are often ductile and can be compacted into pore spaces during burial. The percentage of detrital clay in a rock determines permeability. [[:file:predicting-reservoir-system-quality-and-performance_fig9-63.png|Figure 4]] shows different types of detrital clays in a sandstone.

Detrital clays can be part of sandstone matrix or grains. As matrix, detrital clays can obliterate permeability. Detrital grains of clay are often ductile and can be compacted into pore spaces during burial. The percentage of detrital clay in a rock determines permeability. [[:file:predicting-reservoir-system-quality-and-performance_fig9-63.png|Figure 4]] shows different types of detrital clays in a sandstone.